An isoform of ankyrin is localized at nodes of Ranvier in myelinated axons of central and peripheral nerves.

Published

Journal Article

Two variants of ankyrin have been distinguished in rat brain tissue using antibodies: a broadly distributed isoform (ankyrinB) that represents the major form of ankyrin in brain and another isoform with a restricted distribution (ankyrinR) that shares epitopes with erythrocyte ankyrin. The ankyrinR isoform was localized by immunofluorescence in cryosections of rat spinal cord gray matter and myelinated central and peripheral nerves to: (a) perikarya and initial axonal segments of neuron cells, (b) nodes of Ranvier of myelinated nerve with no detectable labeling in other areas of the myelinated axons, and (c) the axolemma of unmyelinated axons. Immunogold EM on ultrathin cryosections of myelinated nerve showed that ankyrinR was localized on the cytoplasmic face of the axolemma and was restricted to the nodal and, in some cases, paranodal area. The major isoform of ankyrin in brain (ankyrinB) displayed a broad distribution on glial and neuronal cells of the gray matter and a mainly glial distribution in central myelinated axons with no significant labeling on the axolemma. These results show that (a) ankyrin isoforms display a differential distribution on glial and neuronal cells of the nervous tissue; (b) an isoform of ankyrin codistributes with the voltage-dependent sodium channel in both myelinated and unmyelinated nerve fibers. Ankyrin interacts in vitro with the voltage-dependent sodium channel (Srinivasan, Y., L. Elmer, J. Davis, V. Bennett, and K. Angelides. 1988. Nature (Lond.). 333:177-180). A specific interaction of an isoform of ankyrin with the sodium channel thus may play an important role in the morphogenesis and/or maintenance of the node of Ranvier.

Full Text

Duke Authors

Cited Authors

  • Kordeli, E; Davis, J; Trapp, B; Bennett, V

Published Date

  • April 1990

Published In

Volume / Issue

  • 110 / 4

Start / End Page

  • 1341 - 1352

PubMed ID

  • 2139035

Pubmed Central ID

  • 2139035

International Standard Serial Number (ISSN)

  • 0021-9525

Digital Object Identifier (DOI)

  • 10.1083/jcb.110.4.1341

Language

  • eng

Conference Location

  • United States